<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<title></title>
	<link rel="stylesheet" href="">
</head>
<body>
<script src="https://cdn.bootcss.com/vue/2.3.4/vue.js"></script>
<div id="app">
	<ul>
		<li v-for='item in arr'>{{item}}</li>
	</ul>
</div>
<script>
   var app=new Vue({
       el:"#app",
       data:{
           arr:['北京','上海','天津','重庆']
       }
   });
    app.arr[0]='北京天安门';
</script>	
</body>
</html>